2
: beginning, commencement
the onset of winter
the onset of age-related diseases
Examples of onset in a Sentence
the walls withstood the onset of the first battalion
the claim that if you take enough vitamin C at the onset of a cold, you'll often recover faster
Recent Examples on the Web
More importantly, failing to articulate an acceptable mistake at the onset will leave your team without the language to define which levers were most important to drive business goals.
—
Rebecca Shaddix, Forbes.com, 8 Apr. 2025
Measles rash appears three to five days after the onset of the first symptoms.
—USA Today, 7 Apr. 2025
For example, in 2020, markets saw their second-worst day of the year on March 12 at the onset of the Covid pandemic.
—Lorie Konish, CNBC, 7 Apr. 2025
However, consumers should be mindful of dosage and onset time, which can vary based on metabolism.
—Matt Rozo, Mercury News, 4 Apr. 2025
See All Example Sentences for onset
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Rebecca Shaddix, Forbes.com, 8 Apr. 2025
Measles rash appears three to five days after the onset of the first symptoms.
—USA Today, 7 Apr. 2025
For example, in 2020, markets saw their second-worst day of the year on March 12 at the onset of the Covid pandemic.
—Lorie Konish, CNBC, 7 Apr. 2025
However, consumers should be mindful of dosage and onset time, which can vary based on metabolism.
—Matt Rozo, Mercury News, 4 Apr. 2025
See All Example Sentences for onset
Cite this Entry
“Onset.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/onset. Accessed 19 Apr. 2025.
Copy CitationKids Definition
onset
noun
on·set
ˈȯn-ˌset 
ˈän-
Medical Definition
onset
noun
on·set
ˈȯn-ˌset, ˈän-
: the initial existence or symptoms of a disease
the onset of scarlet fever
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